Rogue trails, vandalism vex county park officials as plan is considered

An X Games-like bike jump course near Mill Valley has drawn the attention of the likes of Tiburon Olympic Gold Medalist Jonny Moseley. One problem: County parks officials say it was built illegally.

The series of a dozen or so undulating earthen hills near Vasco Court apparently took years to build, and was discovered by Marin County Parks and Open Space rangers only recently.

Because the handmade course is so developed and near spotted owl and red-legged frog habitat — both species are federally listed under the Endangered Species Act — officials believe it would take an environmental permit to bring it back to its natural condition.

"The first time I saw this, I was like 'oh my God,'" said ranger Robert Ruiz as he looked over the site this week. "How did they do this?"

County officials point to the bike course as one of many examples of rogue uses of public lands. Illegal trails crisscross the thousands of acres of county open space, said Linda Dahl, director and general manager of the district. Bikers and hikers use tools to carve out trails, but in the process damage the habitat of flora and fauna.

"We just can't keep adding trails and trails, or pretty soon the open space looks like a plate of spaghetti," she said.

The county is in the process of developing a plan to manage roads and trails on 16,000 acres of county open space preserves. It will be reviewed Thursday by the parks commission.

The plan covers 34 county open space preserves that are crossed by 270 miles of trails and roads, including 113 miles of fire roads and 335 trailheads. It tightens restrictions, outlines a decision-making matrix that sorts priorities for projects and sets up a series of visitor management zones in which a variety of strategies regulate activity.

It got criticized from some who felt the county was overstepping its bounds by trying to regulate trails.

"People have been building trails in Marin County since these hills were ranched and people believe it's their birthright to do so," Dahl said. "We are concerned about rogue trails; they are very destructive for the environment. We understand people like to get out into nature, but if you build whatever you want wherever you want, pretty soon that nature is gone."

The county parks plan would give amnesty to any trail built before November 2011 with a promise that the practice would stop, Dahl said. Each county preserve would be examined, however, and if a trail was deemed unfit for the area or unsafe it would be removed, she added.

Ranger Ruiz said the bike course near Mill Valley is a prime example.

"See these wood rat nests?" he said, pointing to a wooded clump near one of the bike ramps. "That's what the spotted owls feed on. Having this bike area so close to habitat is problematic."

The bike course is a popular enough location to have drawn the interest of Olympian Moseley, who did a piece on the site as part of "Bikeskills.com: Adventures Part II," which was posted to YouTube. After this article was published, the status of the video was changed to private.

In another county area, 67 trees were felled by people who built an illegal 2.5-mile mountain bike trail at French Ranch Preserve in the San Geronimo Valley. There is also vandalism. On Ring Mountain in Corte Madera, signs posted to keep people out of a burned area were picked up and thrown behind a pile of rocks. Other signs have been similarly damaged in county open space.

"A lot of this goes on at night when we are not there," said Brian Sanford, superintendent with Marin County parks. "It's a game of cat and mouse."

It's not only county parks that have issues with illegal trails.

Last month a lengthy downhill mountain bike trail — complete with wooden ramps, bridges, and jumps — carved out through bay oak woodland and eucalyptus groves was discovered in the Tamalpais Valley off the Miwok Trail, said Frank Dean, superintendent at the Golden Gate National Recreation Area.

"It was elevated in places with boardwalks and jumps; it took quite awhile to build," Dean said. "It was pretty bold."

Dahl said the county plans to step up enforcement. It recently hired nine new rangers and among their duties will be to keep an eye out for illegal trails.

"People tell us who are we to stop these trails," Dahl said. "We are hired by the public to steward these lands."